Content synchronization refers to a technical means of synchronization performed for maintaining consistency of data content between devices or between a device and a server.
Currently, content synchronization includes synchronization of contacts, SMS messages and call records based on the SyncML (Synchronization Markup Language, Synchronization Markup Language), mail synchronization based on the IMAP (Internet Mail Access Protocol, Internet Mail Access Protocol) protocol, and session message synchronization based on the SIP (Session Initiation Protocol, Session Initiation Protocol). These synchronization manners can all implement a function of synchronization between a terminal and a cloud.
However, when content synchronization is performed in the foregoing synchronization manners, a terminal device must initiate a connection for the synchronization, and keep requesting, in a polling manner, from a server whether content is updated. As a result, the load of the terminal device is increased and the processing efficiency of the terminal device is reduced.